I've used Core before and love them, last long, convenient and easy to see what the battery life is at, usb plus ptap in them, but I wanted to hear from other operators who own Core or BCB batteries and what they think of them (particularly BCB).

I can afford the difference but I'm wondering is the price difference between Core and BCB worth it?

I've been using BCB V-mount batteries exclusively for 5 years. I've got 8 of them in all power capacities. They're great and I've never had a problem with them, and they even have versions for the RED cameras that report battery condition on the monitor. I recommend the higher watt-hour models for their higher discharge capacity and extra weight on the rig to help balance bigger camera builds.